Objective To study and test novel hybrid valves in vitro and in vivo, and provide basis for clinical use in future. Methods The hybrid valves were fabricated from decellularized porcine aortic valves coated with poly (3-hydroxybutyrate-co-3hydroxyhexanoate, PHBHHx).（1）In the mechanical test in vitro, the uniaxial tensile biomechanics test of the fresh (n=12), uncoated (n=12) and hybrid valve leaflets (n=12) were investigated. (2）In study in vivo, hybrid valves(n=5) implanted in pulmonary position in sheep without cardiopulmonary bypass. Uncoated grafts (n=5) used as control. The specimens of the hybrid or uncoated valve in sheep were explanted and examined by scanning electron microscopy, histology, calcium content and immunofluorescence staining 18 weeks after surgery. Results The mechanical test in vitro revealed that coating with PHBHHx increased maximal tensile strength of hybrid valves compared with the fresh and uncoated state (P＜0.05). The results in vivo indicated the hybrid valves maintained original shape and softness. Immunofluorescence staining for CD31 confirmed that the surface of hybrid valve was covered by confluent CD31+ cells.The interstitium of hybrid valve indicated that smooth muscle actin (SMA)+ cells population were similar to native valvular tissue. The calcium content of hybrid valve was significantly lower than that of uncoated valve leaflets (P＜0.05). Conclusion Decellularized porcine aortic valves coated with PHBHHx have good biological and biomechanical characteristics. The hybrid valve may provide superior valve replacement with current techniques.
Objective To investigate the impact of three kinds of palliative operation on the body and growth of pulmonary artery in patients with congenital heart diseases of diminutive pulmonary blood. Methods Clinical data was reviewed in 28 cases of congenital heart diseases with diminutive pulmonary blood who had been performed cavopulmonary connection （n = 9）, systemic-pulmonary shunt （n = 8 ）, and palliative reconstruction of right ventricular outflow tract （n=11）. The period between re-hospitalized and the first was 5-54 months （19.07±10. 06 months ）. Hematocrit （HCT）, hemoglobin （Hb）, percutaneous oxygen saturation （SpO2）, body surface area （BSA）, and pulmonary artery index （PAI） etc. were observed both before palliation and before the second operation. Results After the second hospitalization, there were 7 cases of death from hemorrhage, failure of circulation and extracorporeal circulation accident etc. The time of respirator, intensive care unit and total amount of dopamine in patients of palliative reconstruction of right ventricular outflow tract were longer and more than those in patients of cavopulmonary connection （P〈0. 05）. HCT, Hb before the second operation were decreased than thoes before palliative operations in all patients, SpO2, BSA and PAI increased significantly （P 〈 0. 01 ）. Before the second operation, BSA of patients with cavopulmonary connection, BSA and PAI of patients with systemic-pulmonary shunt, SpO2, BSA and PAI of patients with palliative reconstruction of right ventricular outflow tract were increased than those before palliative operations（P〈0. 01）. HCT of palliative reconstruction of right ventricular outflow tract was decreased（P〈0. 05）. Conclusion This results suggests that pulmonary blood of patients with congenital heart diseases of diminutive pulmonary blood can be increased, development of pulmonary arteries can be improved efficiently by systemic-pulmonary shunt and palliative reconstruction of right ventricle outflow tract, but it can not be found in cavopulmonary connection patients.
Objective To investigate the optimal timing for surgical treatment of infants less than six months of age with tetralogy of Fallot (TOF), and to improve surgical results and reduce early mortality. Methods Clinical material of 108 consecutive patients with TOF who were less than six months of age undergoing early surgery from Oct.1996 to Dec. 2006 were retrospectively reviewed. There were 70 males and females with mean age of 4.70 months (9 d-6 months). 104 patients underwent complete repair and four patients underwent BlalockTaussig (B T) shunt. Emergency procedures have been performed in 5 patients. Results Five patients (4.63%) died of low cardiac output syndrome (3 patients), pulmonary infection and acute respiratory distress syndrome (1 patient), and acute necrotizing enteritis (1 patient).82 patients were followed up, followup period was 31.17±40.00 months.21 patients lost to followup. One patient(0.92%) required additional intervention for pulmonary valve stenosis 6 months after operation. Heart functional class(New York Heart Association) recovered toⅠ-Ⅱgrading in other patients. Echocardiography shows: no residual ventricular shunt, no stenosis in right ventricular outflow tract and pulmonary valve, pressure difference≤50 mm Hg. No late deaths. Conclusion Early definitive repair of TOF can be performed safely on infants less than six months of age, the results of low mortality is acceptable.
Abstract: Objective To summarize the clinical experience for complex congenital heart disease treated with modified Fontan operation. Methods From November 1996 to May 2005,124 patients (male 83,female 41; including tricuspid atresia, single ventricle, double outlet of right ventricle, malposition of great arteries, pulmonary atresia, corrected transposition of great arteries, hypoplastic rightheart syndrome, etc.) underwent modified Fontan operation at age 7.6±5.5 years. Noncardiopulmonary bypass was used in 19 patients, 105 patients with cardiopulmonary bypass. Right atria-pulmonary artery connection were performed in 17 patients, right atria-ventricular connection were performed in 19 patients, and total cavopulmonary connection (TCPC) were performed in 88 patients. Staged operation were performed in 23 patients. Results The hospital mortality (30 days postoperative) was 13.7% (17/124). The hospital mortality of patients undergone right atria-pulmonary artery connection was 23.5%(4/17), patients undergone right atria-ventricular connection was 15.8%(3/19), patients undergone TCPC was 11.4%(10/88), patients undergone operation with fenestration was 14.6%(6/41), and the patients undergone staged operation was 8.7%(2/23). Low cardiac output syndrome, multiple organ failure, and ventricular fibrillation were the cause of death. Morbidity of complications was 16.9％(21/124) in early period. Complications consisted of pleural effusion, arrhythmia, pericardial effusion and low cardiac output syndrome, etc. Eightynine patients were followed up, followup time was from postoperative 6 months to 65 months. Re-hospitalization rate was 6.5%, and re-operation rate was 0.9%. There were pleural effusion in 3 patients, pericardial effusion in 3 patients, and obstruction of inferior vena cava in 1 patient. All patients recovered. Conclusion Modified Fontan operation is an optimal procedure for functional single ventricle, fenestration seems to decrease postoperative pleural effusions.
Objective To explore morphological recellularization level of bioprosthetic valve scaffold (BVS) and to provide researching means for fabricating tissue engineered heart valve in vitro.Methods The homograft bioprosthetic aortic tube valve was selected as BVS, which was conserved by liquid nitrogen, and its endothelial cells (ECs) were removed by 0.1% sodium dodecylsulphate (SDS). As implantation cells, the endothelial cells (ECs) differentiating from human bone marrow mesenchymal stem cells (MSCs) in vitro were implanted with high-density seeding (gt;10 5 cells/cm2) on the BVS, which was covered by fibronectin (80 μg/ml) in advance. The complex structure was statically cultured in DMEM (high glucose) with 20% FBS and VEGF (10 ng/ml) for about 20 days in vitro and stained by 0.5% AgNO3. The morphological structure was observed and photographed by stereomicroscope to detect the recellularization level. Results The ECs of the bioprosthetic valve were notonly removed completely, but also the collagen fiber and elastic fibers were reserved. The ECs differentiating from MSCs were successfully implanted on the HBS, whose recellularization levels on 7th, 14th and 20th day were 73%, 85%, and 92% respectively. Conclusion AgNO3 staining technique is effective, convenient, and economic in evaluating the recellularization level of BVS. It is an effective method in morphological observation for fabricating tissueengineered heart valve in vitro.